I have been looking for an SRT as well. I don't think anyone is making this. I did find a 1:24 Limited model available in multiple colors from Motor Max.
http://www.motormaxtoy.com/search?term=crossfire
I bought one in black and changed out the wheels. The car cost only $9 but the wheels and tires cost $10. I am now working on chin and tail spoilers and some kind of overlay for the engine (the hood and doors open) But I started 2 months ago and have made no progress yet.
If anyone picks up on this, please post how you did it.
Yes that is a Sterling Grey Z4 in the background...just like the one I traded in for my SRT6.